diff --git a/NAMESPACE b/NAMESPACE
index 464c706..1a2ffa4 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1,11 +1,8 @@
 # Generated by roxygen2: do not edit by hand
 
 export(bpmnVisualizationROutput)
-export(create_fill)
-export(create_font)
 export(create_overlay)
-export(create_stroke)
-export(create_style)
+export(create_overlay_style)
 export(display)
 export(overlay_edge_position)
 export(overlay_shape_position)
diff --git a/R/bpmnVisualizationR.R b/R/bpmnVisualizationR.R
index 61779be..083cba0 100644
--- a/R/bpmnVisualizationR.R
+++ b/R/bpmnVisualizationR.R
@@ -38,10 +38,10 @@
 #' # Load the BPMN file
 #' bpmn_file <- system.file("examples/Order_Management.bpmn", package = "bpmnVisualizationR")
 #'
-#' # Display the BPMN diagram
+#' # Example 1: Display the BPMN diagram
 #' bpmnVisualizationR::display(bpmn_file, width='auto', height='auto')
 #'
-#' # Display the BPMN diagram featuring overlays with their default positions and styles
+#' # Example 2: Display the BPMN diagram featuring overlays with their default positions and styles
 #' overlays <- list(
 #'   bpmnVisualizationR::create_overlay("start_event_1_1", "42"),
 #'   bpmnVisualizationR::create_overlay("sequence_flow_1_1", "42"),
@@ -49,6 +49,7 @@
 #'   bpmnVisualizationR::create_overlay("sequence_flow_1_2", "8"),
 #'   bpmnVisualizationR::create_overlay("call_activity_1_1", "7")
 #' )
+#'
 #' bpmnVisualizationR::display(
 #'   bpmn_file,
 #'   overlays,
@@ -56,17 +57,19 @@
 #'   height='auto'
 #' )
 #'
-#' # Display the BPMN diagram featuring overlays using custom styles and positions
-#' taskStyle <- bpmnVisualizationR::create_style(
-#'   font = bpmnVisualizationR::create_font(color = 'DarkSlateGray', size = 23),
-#'   fill = bpmnVisualizationR::create_fill(color = 'MistyRose'),
-#'   stroke = bpmnVisualizationR::create_stroke(color = 'Red')
+#' # Example 3: Display the BPMN diagram featuring overlays using custom styles and positions
+#' taskStyle <- bpmnVisualizationR::create_overlay_style(
+#'   font_color = 'DarkSlateGray',
+#'   font_size = 23,
+#'   fill_color = 'MistyRose',
+#'   stroke_color = 'Red'
 #' )
 #'
-#' flowStyle <- bpmnVisualizationR::create_style(
-#'   font = bpmnVisualizationR::create_font(color = 'WhiteSmoke', size = 19),
-#'   fill = bpmnVisualizationR::create_fill(color = 'Teal'),
-#'   stroke = bpmnVisualizationR::create_stroke(color = 'SpringGreen')
+#' flowStyle <- bpmnVisualizationR::create_overlay_style(
+#'   font_color = 'WhiteSmoke',
+#'   font_size = 19,
+#'   fill_color = 'Teal',
+#'   stroke_color = 'SpringGreen'
 #' )
 #'
 #' overlays <- list(
@@ -78,13 +81,15 @@
 #' )
 #' bpmnVisualizationR::display(bpmn_file, overlays, width='auto', height='auto')
 #'
-#' # Display the BPMN diagram featuring overlays, but exclude their default styles and positions
+#' # Example 4: Display the BPMN diagram featuring overlays, 
+#' # but exclude their default styles and positions
 #' overlays <- list(
 #'   bpmnVisualizationR::create_overlay("start_event_1_1", "42", position = "middle-left"),
 #'   bpmnVisualizationR::create_overlay("sequence_flow_1_1", "42", flowStyle, "end"),
 #'   bpmnVisualizationR::create_overlay("task_1_1", "9", taskStyle, "bottom-right"),
 #'   bpmnVisualizationR::create_overlay("sequence_flow_1_2", "8",  position = 'start')
 #' )
+#'
 #' bpmnVisualizationR::display(
 #'   bpmn_file,
 #'   overlays,
diff --git a/R/funs.R b/R/funs.R
index 8da3cc8..c9b62c8 100644
--- a/R/funs.R
+++ b/R/funs.R
@@ -3,33 +3,62 @@
 #' @description
 #' To specify the position when creating an overlay object that will be attached to BPMN \code{Shape} elements in the diagram.
 #'
-#' \code{overlay_shape_position} includes the following positions:
-#'
-#' - \code{"top-left"}
-#' - \code{"top-right"}
-#' - \code{"top-center"}
-#' - \code{"bottom-left"}
-#' - \code{"bottom-right"}
-#' - \code{"bottom-center"}
-#' - \code{"middle-left"}
-#' - \code{"middle-right"}
-#'
+#' @details
 #' Use these constants as the \code{position} argument in the \code{\link{create_overlay}} function.
 #'
+#' @section Positions:
+#'  \itemize{
+#'    \item{\code{top-left}}{}
+#'    \item{\code{top-right}}{}
+#'    \item{\code{top-center}}{}
+#'    \item{\code{bottom-left}}{}
+#'    \item{\code{bottom-right}}{}
+#'    \item{\code{bottom-center}}{}
+#'    \item{\code{middle-left}}{}
+#'    \item{\code{middle-right}}{}
+#'  }
+#'  
+#' @seealso
+#' \code{\link{create_overlay}}
+#' 
+#' @examples
+#' # Create an overlay at the top-left corner of a shape
+#' overlay <- create_overlay(elementId = 1, label = "My label", position = overlay_shape_position[1])
+#'
 #' @export
-overlay_shape_position <- c("top-left", "top-right", "top-center", "bottom-left", "bottom-right", "bottom-center", "middle-left", "middle-right")
+overlay_shape_position <-
+  c(
+    "top-left",
+    "top-right",
+    "top-center",
+    "bottom-left",
+    "bottom-right",
+    "bottom-center",
+    "middle-left",
+    "middle-right"
+  )
 
 #' @title The overlay positions on \code{Edge}
 #'
 #' @description
 #' To specify the position when creating an overlay object that will be attached to BPMN \code{Edge} elements in the diagram.
+#' 
+#' @details
+#' Use these constants as the \code{position} argument in the \code{\link{create_overlay}} function.
 #'
-#' \code{overlay_edge_position} includes the following positions:
-#' - \code{"start"}
-#' - \code{"end"}
-#' - \code{"middle"}
+#' @section Positions:
+#'  \itemize{
+#'    \item{\code{start}}{}
+#'    \item{\code{end}}{}
+#'    \item{\code{middle}}{}
+#'  }
 #'
-#' Use these constants as the \code{position} argument in the \code{\link{create_overlay}} function.
+#' @seealso
+#' \code{\link{create_overlay}}
+#'
+#' @examples
+#' # Create an overlay at the starting point of an edge
+#' overlay <- create_overlay(elementId = 1, label = "My label", position = overlay_edge_position[1])
 #' 
 #' @export
 overlay_edge_position <- c("start", "end", "middle")
@@ -47,7 +76,7 @@ overlay_edge_position <- c("start", "end", "middle")
 #' @param elementId The bpmn element id to which the overlay will be attached
 #' @param label 'HTML' element to use as an overlay
 #' @param style The style of the overlay.
-#'      Use \code{\link{create_style}} function to create the style object of an overlay and be aware of the `enableDefaultOverlayStyle` parameter in the \code{\link{display}} function.
+#'      Use \code{\link{create_overlay_style}} function to create the style object of an overlay and be aware of the `enableDefaultOverlayStyle` parameter in the \code{\link{display}} function.
 #' @param position The position of the overlay
 #'      If the bpmn element where the overlay will be attached is a Shape, use \code{\link{overlay_shape_position}}.
 #'      Otherwise, use \code{\link{overlay_edge_position}}.
@@ -55,28 +84,34 @@ overlay_edge_position <- c("start", "end", "middle")
 #' @returns An overlay object
 #'
 #' @examples
-#' # Create an overlay with shape position "top-left"
+#' # Example 1: Create an overlay with shape position "top-left"
+#' overlay_style <- create_overlay_style(
+#'   font_color = 'DarkSlateGray',
+#'   font_size = 23,
+#'   fill_color = 'MistyRose',
+#'   stroke_color = 'Red'
+#' )
+#'
 #' overlay <- create_overlay(
-#'   "my-element-id", 
-#'   "My Overlay Label", 
-#'   create_style(
-#'     font = create_font(color = 'DarkSlateGray', size = 23),
-#'     fill = create_fill(color = 'MistyRose'),
-#'     stroke = create_stroke(color = 'Red')
-#'   ),
-#'   overlay_shape_position[1]
+#'   "my-shape-id",
+#'   "My Overlay Label",
+#'   style = overlay_style,
+#'   position = overlay_shape_position[1]
+#' )
+#'
+#' # Example 2: Create an overlay with edge position "end"
+#' overlay_style <- create_overlay_style(
+#'   font_color = 'DarkSlateGray',
+#'   font_size = 23,
+#'   fill_color = 'MistyRose',
+#'   stroke_color = 'Red'
 #' )
 #'
-#' # Create an overlay with edge position "end"
 #' overlay <- create_overlay(
-#'   "my-edge-id", 
-#'   "My Overlay Label", 
-#'   create_style(
-#'     font = create_font(color = 'DarkSlateGray', size = 23),
-#'     fill = create_fill(color = 'MistyRose'),
-#'     stroke = create_stroke(color = 'Red')
-#'   ),
-#'   overlay_edge_position[2]
+#'   "my-edge-id",
+#'   "My Overlay Label",
+#'   style = overlay_style,
+#'   position = overlay_edge_position[2]
 #' )
 #'
 #' @export
@@ -102,7 +137,7 @@ create_overlay <- function(elementId, label, style = NULL, position = NULL) {
 
 #' @title Create the style of an overlay
 #'
-#' @name create_style
+#' @name create_overlay_style
 #' @description
 #' When adding an overlay to an existing element in a diagram, it's possible to customize its style.
 #'
@@ -110,41 +145,44 @@ create_overlay <- function(elementId, label, style = NULL, position = NULL) {
 #'
 #' Use this function to create the correct style structure for an overlay.
 #'
-#' @param font The font style of the overlay
-#'      Use \code{\link{create_font}} function to create the font style object for the overlay.
-#' @param fill The fill style of the overlay
-#'      Use \code{\link{create_fill}} function to create the fill style object for the overlay.
-#' @param stroke The stroke style of the overlay
-#'      Use \code{\link{create_stroke}} function to create the stroke style object for the overlay.
+#' @param font_color The font color of the overlay. Use all HTML color names or HEX codes.
+#' @param font_size The font size of the overlay. Specify a number in px.
+#' @param fill_color The color of the background of the overlay. Use all HTML color names or HEX codes.
+#' @param stroke_color The color of the stroke of the overlay. Use all HTML color names or HEX codes.
+#'      If you don't want to display a stroke, you can set the color to:
+#'      - \code{transparent},
+#'      - the same value as for the \code{fill_color}. This increases the \code{padding}/\code{margin}.
 #'
 #' @returns The style object of the overlay
 #'
 #' @export
-create_style <- function(font = NULL, fill = NULL, stroke = NULL) {
+create_overlay_style <- function(font_color = NULL,
+                                 font_size = NULL,
+                                 fill_color = NULL,
+                                 stroke_color = NULL) {
   ret <-
     .not_null_list(
-      font = font,
-      fill = fill,
-      stroke = stroke
+      font = create_font(color = font_color, size = font_size),
+      fill = create_fill(fill_color),
+      stroke = create_stroke(stroke_color)
     )
 }
 
-#' @title Create the font style of an overlay
+#' @title Internal function to create the font style of an overlay or a 'BPMN' element
 #'
 #' @name create_font
 #' @description
-#' When adding an overlay to an existing element in a diagram, it's possible to customize its font style.
-#'
-#' Refer to the \code{font} parameter in the \code{\link{create_style}} function for more information.
-#'
-#' Use this function to create the correct font structure for an overlay.
+#' - Overlay:
+#'  When adding an overlay to an existing element in a diagram, it's possible to customize its font style.
+#'  Refer to the \code{font} parameter in the \code{\link{create_overlay_style}} function for more information.
+#'  Use this function to create the correct font structure for an overlay.
 #'
 #' @param color The color of the font of the overlay
 #' @param size The size of the font of the overlay
 #'
 #' @returns The font style object of the overlay
 #'
-#' @export
+#' @noRd
 create_font <- function(color = NULL, size = NULL) {
   ret <-
     .not_null_list(
@@ -153,21 +191,20 @@ create_font <- function(color = NULL, size = NULL) {
     )
 }
 
-#' @title Create the fill style of an overlay
+#' @title Internal function to create the fill style of an overlay or a 'BPMN' element
 #'
 #' @name create_fill
 #' @description
-#' When adding an overlay to an existing element in a diagram, it's possible to customize how it is filled.
-#'
-#' Refer to the \code{fill} parameter in the \code{\link{create_style}} function for more information.
-#'
-#' Use this function to create the correct fill structure for an overlay.
+#' - Overlay:
+#'  When adding an overlay to an existing element in a diagram, it's possible to customize how it is filled.
+#'  Refer to the \code{fill} parameter in the \code{\link{create_overlay_style}} function for more information.
+#'  Use this function to create the correct fill structure for an overlay.
 #'
 #' @param color The color of the background of the overlay
 #'
 #' @returns The fill style object of the overlay
 #'
-#' @export
+#' @noRd
 create_fill <- function(color) {
   ret <-
     .not_null_list(
@@ -175,21 +212,20 @@ create_fill <- function(color) {
     )
 }
 
-#' @title Create the stroke style of an overlay
+#' @title Internal function to create the stroke style of an overlay or a 'BPMN' element
 #'
 #' @name create_stroke
 #' @description
-#' When adding an overlay to an existing element in a diagram, it's possible to customize its stroke. style.
-#'
-#' Refer to the \code{stroke.} parameter in the \code{\link{create_style}} function for more information.
-#' 
-#' Use this function to create the correct stroke structure for an overlay.
+#' - Overlay:
+#'  When adding an overlay to an existing element in a diagram, it's possible to customize its stroke. style.
+#'  Refer to the \code{stroke.} parameter in the \code{\link{create_overlay_style}} function for more information.
+#'  Use this function to create the correct stroke structure for an overlay.
 #'
 #' @param color The color of the stroke of the overlay
 #'
 #' @returns The stroke style object of the overlay
 #'
-#' @export
+#' @noRd
 create_stroke <- function(color) {
   ret <-
     .not_null_list(
@@ -197,7 +233,7 @@ create_stroke <- function(color) {
     )
 }
 
-#' @description Internal fun to build the 'htmlwidget' content
+#' @description Internal function to build the 'htmlwidget' content
 #'
 #' @inheritParams display
 #' @returns A list
diff --git a/README.md b/README.md
index 52f0102..734aa84 100644
--- a/README.md
+++ b/README.md
@@ -115,11 +115,13 @@ bpmnVisualizationR::display(bpmn_file, overlays)
 ### Style an overlay
 
 ```r
-font <- bpmnVisualizationR::create_font(color = 'WhiteSmoke', size = 19)
-fill <- bpmnVisualizationR::create_fill(color = 'Teal')
-stroke <- bpmnVisualizationR::create_stroke(color = 'SpringGreen')
+style <- bpmnVisualizationR::create_overlay_style(
+  font_color = 'WhiteSmoke',
+  font_size = 19,
+  fill_color = 'Teal',
+  stroke_color = 'SpringGreen'
+)
 
-style <- bpmnVisualizationR::create_style(font, fill, stroke)
 overlay <- bpmnVisualizationR::create_overlay("bpmn_element_id_1", "42", style, "middle-right")
 ```
 
@@ -143,10 +145,11 @@ library(shiny)
 
 displayBpmn <- function() {
     bpmn_file <- system.file("examples/Travel_Booking.bpmn", package = "bpmnVisualizationR")
-    style <- bpmnVisualizationR::create_style(
-      font = bpmnVisualizationR::create_font(color = 'Black', size = 25), 
-      fill = bpmnVisualizationR::create_fill(color = 'MediumSpringGreen'), 
-      stroke = bpmnVisualizationR::create_stroke(color = 'MediumSpringGreen')
+    style <- bpmnVisualizationR::create_overlay_style(
+      font_color = 'Black',
+      font_size = 25,
+      fill_color = 'MediumSpringGreen',
+      stroke_color = 'MediumSpringGreen'
     )
     overlays <- list(bpmnVisualizationR::create_overlay("_6-203", "9", style, "bottom-right"))
     bpmnVisualizationR::display(bpmn_file, overlays)
diff --git a/man/create_fill.Rd b/man/create_fill.Rd
deleted file mode 100644
index e1bded9..0000000
--- a/man/create_fill.Rd
+++ /dev/null
@@ -1,21 +0,0 @@
-% Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/funs.R
-\name{create_fill}
-\alias{create_fill}
-\title{Create the fill style of an overlay}
-\usage{
-create_fill(color)
-}
-\arguments{
-\item{color}{The color of the background of the overlay}
-}
-\value{
-The fill style object of the overlay
-}
-\description{
-When adding an overlay to an existing element in a diagram, it's possible to customize how it is filled.
-
-Refer to the \code{fill} parameter in the \code{\link{create_style}} function for more information.
-
-Use this function to create the correct fill structure for an overlay.
-}
diff --git a/man/create_font.Rd b/man/create_font.Rd
deleted file mode 100644
index 7d87c17..0000000
--- a/man/create_font.Rd
+++ /dev/null
@@ -1,23 +0,0 @@
-% Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/funs.R
-\name{create_font}
-\alias{create_font}
-\title{Create the font style of an overlay}
-\usage{
-create_font(color = NULL, size = NULL)
-}
-\arguments{
-\item{color}{The color of the font of the overlay}
-
-\item{size}{The size of the font of the overlay}
-}
-\value{
-The font style object of the overlay
-}
-\description{
-When adding an overlay to an existing element in a diagram, it's possible to customize its font style.
-
-Refer to the \code{font} parameter in the \code{\link{create_style}} function for more information.
-
-Use this function to create the correct font structure for an overlay.
-}
diff --git a/man/create_overlay.Rd b/man/create_overlay.Rd
index 91ea382..e9ef687 100644
--- a/man/create_overlay.Rd
+++ b/man/create_overlay.Rd
@@ -12,7 +12,7 @@ create_overlay(elementId, label, style = NULL, position = NULL)
 \item{label}{'HTML' element to use as an overlay}
 
 \item{style}{The style of the overlay.
-Use \code{\link{create_style}} function to create the style object of an overlay and be aware of the `enableDefaultOverlayStyle` parameter in the \code{\link{display}} function.}
+Use \code{\link{create_overlay_style}} function to create the style object of an overlay and be aware of the `enableDefaultOverlayStyle` parameter in the \code{\link{display}} function.}
 
 \item{position}{The position of the overlay
 If the bpmn element where the overlay will be attached is a Shape, use \code{\link{overlay_shape_position}}.
@@ -29,28 +29,34 @@ See the \code{overlays} argument in the \code{\link{display}} function.
 Use this function to create the correct overlay structure.
 }
 \examples{
-# Create an overlay with shape position "top-left"
+# Example 1: Create an overlay with shape position "top-left"
+overlay_style <- create_overlay_style(
+  font_color = 'DarkSlateGray',
+  font_size = 23,
+  fill_color = 'MistyRose',
+  stroke_color = 'Red'
+)
+
 overlay <- create_overlay(
-  "my-element-id", 
-  "My Overlay Label", 
-  create_style(
-    font = create_font(color = 'DarkSlateGray', size = 23),
-    fill = create_fill(color = 'MistyRose'),
-    stroke = create_stroke(color = 'Red')
-  ),
-  overlay_shape_position[1]
+  "my-shape-id",
+  "My Overlay Label",
+  style = overlay_style,
+  position = overlay_shape_position[1]
+)
+
+# Example 2: Create an overlay with edge position "end"
+overlay_style <- create_overlay_style(
+  font_color = 'DarkSlateGray',
+  font_size = 23,
+  fill_color = 'MistyRose',
+  stroke_color = 'Red'
 )
 
-# Create an overlay with edge position "end"
 overlay <- create_overlay(
-  "my-edge-id", 
-  "My Overlay Label", 
-  create_style(
-    font = create_font(color = 'DarkSlateGray', size = 23),
-    fill = create_fill(color = 'MistyRose'),
-    stroke = create_stroke(color = 'Red')
-  ),
-  overlay_edge_position[2]
+  "my-edge-id",
+  "My Overlay Label",
+  style = overlay_style,
+  position = overlay_edge_position[2]
 )
 
 }
diff --git a/man/create_overlay_style.Rd b/man/create_overlay_style.Rd
new file mode 100644
index 0000000..d5d2b68
--- /dev/null
+++ b/man/create_overlay_style.Rd
@@ -0,0 +1,35 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/funs.R
+\name{create_overlay_style}
+\alias{create_overlay_style}
+\title{Create the style of an overlay}
+\usage{
+create_overlay_style(
+  font_color = NULL,
+  font_size = NULL,
+  fill_color = NULL,
+  stroke_color = NULL
+)
+}
+\arguments{
+\item{font_color}{The font color of the overlay. Use all HTML color names or HEX codes.}
+
+\item{font_size}{The font size of the overlay. Specify a number in px.}
+
+\item{fill_color}{The color of the background of the overlay. Use all HTML color names or HEX codes.}
+
+\item{stroke_color}{The color of the stroke of the overlay. Use all HTML color names or HEX codes.
+If you don't want to display a stroke, you can set the color to:
+- \code{transparent},
+- the same value as for the \code{fill_color}. This increases the \code{padding}/\code{margin}.}
+}
+\value{
+The style object of the overlay
+}
+\description{
+When adding an overlay to an existing element in a diagram, it's possible to customize its style.
+
+Refer to the \code{style} parameter in the \code{\link{create_overlay}} function for more information.
+
+Use this function to create the correct style structure for an overlay.
+}
diff --git a/man/create_stroke.Rd b/man/create_stroke.Rd
deleted file mode 100644
index 8a22ad9..0000000
--- a/man/create_stroke.Rd
+++ /dev/null
@@ -1,21 +0,0 @@
-% Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/funs.R
-\name{create_stroke}
-\alias{create_stroke}
-\title{Create the stroke style of an overlay}
-\usage{
-create_stroke(color)
-}
-\arguments{
-\item{color}{The color of the stroke of the overlay}
-}
-\value{
-The stroke style object of the overlay
-}
-\description{
-When adding an overlay to an existing element in a diagram, it's possible to customize its stroke. style.
-
-Refer to the \code{stroke.} parameter in the \code{\link{create_style}} function for more information.
-
-Use this function to create the correct stroke structure for an overlay.
-}
diff --git a/man/create_style.Rd b/man/create_style.Rd
deleted file mode 100644
index b79d247..0000000
--- a/man/create_style.Rd
+++ /dev/null
@@ -1,28 +0,0 @@
-% Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/funs.R
-\name{create_style}
-\alias{create_style}
-\title{Create the style of an overlay}
-\usage{
-create_style(font = NULL, fill = NULL, stroke = NULL)
-}
-\arguments{
-\item{font}{The font style of the overlay
-Use \code{\link{create_font}} function to create the font style object for the overlay.}
-
-\item{fill}{The fill style of the overlay
-Use \code{\link{create_fill}} function to create the fill style object for the overlay.}
-
-\item{stroke}{The stroke style of the overlay
-Use \code{\link{create_stroke}} function to create the stroke style object for the overlay.}
-}
-\value{
-The style object of the overlay
-}
-\description{
-When adding an overlay to an existing element in a diagram, it's possible to customize its style.
-
-Refer to the \code{style} parameter in the \code{\link{create_overlay}} function for more information.
-
-Use this function to create the correct style structure for an overlay.
-}
diff --git a/man/display.Rd b/man/display.Rd
index ef7d5bf..f847210 100644
--- a/man/display.Rd
+++ b/man/display.Rd
@@ -44,10 +44,10 @@ Display 'BPMN' diagram based on 'BPMN' definition in 'XML' format
 # Load the BPMN file
 bpmn_file <- system.file("examples/Order_Management.bpmn", package = "bpmnVisualizationR")
 
-# Display the BPMN diagram
+# Example 1: Display the BPMN diagram
 bpmnVisualizationR::display(bpmn_file, width='auto', height='auto')
 
-# Display the BPMN diagram featuring overlays with their default positions and styles
+# Example 2: Display the BPMN diagram featuring overlays with their default positions and styles
 overlays <- list(
   bpmnVisualizationR::create_overlay("start_event_1_1", "42"),
   bpmnVisualizationR::create_overlay("sequence_flow_1_1", "42"),
@@ -55,6 +55,7 @@ overlays <- list(
   bpmnVisualizationR::create_overlay("sequence_flow_1_2", "8"),
   bpmnVisualizationR::create_overlay("call_activity_1_1", "7")
 )
+
 bpmnVisualizationR::display(
   bpmn_file,
   overlays,
@@ -62,17 +63,19 @@ bpmnVisualizationR::display(
   height='auto'
 )
 
-# Display the BPMN diagram featuring overlays using custom styles and positions
-taskStyle <- bpmnVisualizationR::create_style(
-  font = bpmnVisualizationR::create_font(color = 'DarkSlateGray', size = 23),
-  fill = bpmnVisualizationR::create_fill(color = 'MistyRose'),
-  stroke = bpmnVisualizationR::create_stroke(color = 'Red')
+# Example 3: Display the BPMN diagram featuring overlays using custom styles and positions
+taskStyle <- bpmnVisualizationR::create_overlay_style(
+  font_color = 'DarkSlateGray',
+  font_size = 23,
+  fill_color = 'MistyRose',
+  stroke_color = 'Red'
 )
 
-flowStyle <- bpmnVisualizationR::create_style(
-  font = bpmnVisualizationR::create_font(color = 'WhiteSmoke', size = 19),
-  fill = bpmnVisualizationR::create_fill(color = 'Teal'),
-  stroke = bpmnVisualizationR::create_stroke(color = 'SpringGreen')
+flowStyle <- bpmnVisualizationR::create_overlay_style(
+  font_color = 'WhiteSmoke',
+  font_size = 19,
+  fill_color = 'Teal',
+  stroke_color = 'SpringGreen'
 )
 
 overlays <- list(
@@ -84,13 +87,15 @@ overlays <- list(
 )
 bpmnVisualizationR::display(bpmn_file, overlays, width='auto', height='auto')
 
-# Display the BPMN diagram featuring overlays, but exclude their default styles and positions
+# Example 4: Display the BPMN diagram featuring overlays, 
+# but exclude their default styles and positions
 overlays <- list(
   bpmnVisualizationR::create_overlay("start_event_1_1", "42", position = "middle-left"),
   bpmnVisualizationR::create_overlay("sequence_flow_1_1", "42", flowStyle, "end"),
   bpmnVisualizationR::create_overlay("task_1_1", "9", taskStyle, "bottom-right"),
   bpmnVisualizationR::create_overlay("sequence_flow_1_2", "8",  position = 'start')
 )
+
 bpmnVisualizationR::display(
   bpmn_file,
   overlays,
diff --git a/man/overlay_edge_position.Rd b/man/overlay_edge_position.Rd
index c7909c9..4961537 100644
--- a/man/overlay_edge_position.Rd
+++ b/man/overlay_edge_position.Rd
@@ -12,12 +12,25 @@ overlay_edge_position
 }
 \description{
 To specify the position when creating an overlay object that will be attached to BPMN \code{Edge} elements in the diagram.
+}
+\details{
+Use these constants as the \code{position} argument in the \code{\link{create_overlay}} function.
+}
+\section{Positions}{
 
-\code{overlay_edge_position} includes the following positions:
-- \code{"start"}
-- \code{"end"}
-- \code{"middle"}
+ \itemize{
+   \item{\code{start}}{}
+   \item{\code{end}}{}
+   \item{\code{middle}}{}
+ }
+}
 
-Use these constants as the \code{position} argument in the \code{\link{create_overlay}} function.
+\examples{
+# Create an overlay at the starting point of an edge
+overlay <- create_overlay(elementId = 1, label = "My label", position = overlay_edge_position[1])
+
+}
+\seealso{
+\code{\link{create_overlay}}
 }
 \keyword{datasets}
diff --git a/man/overlay_shape_position.Rd b/man/overlay_shape_position.Rd
index e926387..82231a9 100644
--- a/man/overlay_shape_position.Rd
+++ b/man/overlay_shape_position.Rd
@@ -12,18 +12,30 @@ overlay_shape_position
 }
 \description{
 To specify the position when creating an overlay object that will be attached to BPMN \code{Shape} elements in the diagram.
+}
+\details{
+Use these constants as the \code{position} argument in the \code{\link{create_overlay}} function.
+}
+\section{Positions}{
 
-\code{overlay_shape_position} includes the following positions:
+ \itemize{
+   \item{\code{top-left}}{}
+   \item{\code{top-right}}{}
+   \item{\code{top-center}}{}
+   \item{\code{bottom-left}}{}
+   \item{\code{bottom-right}}{}
+   \item{\code{bottom-center}}{}
+   \item{\code{middle-left}}{}
+   \item{\code{middle-right}}{}
+ }
+}
 
-- \code{"top-left"}
-- \code{"top-right"}
-- \code{"top-center"}
-- \code{"bottom-left"}
-- \code{"bottom-right"}
-- \code{"bottom-center"}
-- \code{"middle-left"}
-- \code{"middle-right"}
+\examples{
+# Create an overlay at the top-left corner of a shape
+overlay <- create_overlay(elementId = 1, label = "My label", position = overlay_shape_position[1])
 
-Use these constants as the \code{position} argument in the \code{\link{create_overlay}} function.
+}
+\seealso{
+\code{\link{create_overlay}}
 }
 \keyword{datasets}
diff --git a/tests/testthat/test-funs.R b/tests/testthat/test-funs.R
index fa08649..ec51e75 100644
--- a/tests/testthat/test-funs.R
+++ b/tests/testthat/test-funs.R
@@ -1,7 +1,7 @@
 describe("create_overlay works", {
   test_that("with label, style and position", {
     res <- create_overlay("xyz", "this", "my style", "start")
-    
+
     expect_true(length(res) == 4)
     expect_named(res, c("elementId", "label", "style", "position"))
     expect_equal(res$elementId, "xyz")
@@ -9,140 +9,153 @@ describe("create_overlay works", {
     expect_equal(res$style, "my style")
     expect_equal(res$position, "start")
   })
-  
+
   test_that("with no label, style and position", {
     res <- create_overlay("this", NULL, "my style", "middle")
-    
+
     expect_true(length(res) == 3)
-    expect_named(res,  c("elementId", "style", "position"))
+    expect_named(res, c("elementId", "style", "position"))
     expect_equal(res$elementId, "this")
     expect_equal(res$style, "my style")
     expect_equal(res$position, "middle")
   })
-  
+
   test_that("with label, no style, and position", {
     res <- create_overlay("this", "my label", NULL, "top-center")
-    
+
     expect_true(length(res) == 3)
     expect_named(res, c("elementId", "label", "position"))
     expect_equal(res$elementId, "this")
     expect_equal(res$label, "my label")
     expect_equal(res$position, "top-center")
   })
-  
+
   test_that("with label, style, and no position", {
     res <- create_overlay("this", "my label", "my style", NULL)
-    
+
     expect_true(length(res) == 3)
     expect_named(res, c("elementId", "label", "style"))
     expect_equal(res$elementId, "this")
     expect_equal(res$label, "my label")
     expect_equal(res$style, "my style")
   })
-  
+
   test_that("throws an exception when position is not valid", {
     expect_error(
-      create_overlay("this", "my label", "my style", position = "invalid_position"), 
+      create_overlay("this", "my label", "my style", position = "invalid_position"),
       "position must be"
     )
   })
 })
 
-describe("create_style works", {
-  test_that("with font, fill and stroke", {
-    res <- create_style("my font", "my fill", "my stroke")
-    
-    expect_true(length(res) == 3)
+describe("create_overlay_style works", {
+  test_that("with font, fill, and stroke", {
+    res <- create_overlay_style(
+      font_color = "my font color",
+      font_size = "my font size",
+      fill_color = "my fill color",
+      stroke_color = "my stroke color"
+    )
+
+    expect_type(res, "list")
+    expect_length(res, 3)
     expect_named(res, c("font", "fill", "stroke"))
-    expect_equal(res$font, "my font")
-    expect_equal(res$fill, "my fill")
-    expect_equal(res$stroke, "my stroke")
-  })
-  
-  test_that("with no font, fill and stroke", {
-    res <- create_style(NULL, "my fill", "my stroke")
-    
-    expect_true(length(res) == 2)
+
+    expect_equal(res$font, list(color = "my font color", size = "my font size"))
+    expect_equal(res$fill, list(color = "my fill color"))
+    expect_equal(res$stroke, list(color = "my stroke color"))
+  })
+
+  test_that("with no font, fill, and stroke", {
+    res <- create_overlay_style(fill_color = "my fill color", stroke_color = "my stroke color")
+
+    expect_type(res, "list")
+    expect_length(res, 2)
     expect_named(res, c("fill", "stroke"))
-    expect_equal(res$fill, "my fill")
-    expect_equal(res$stroke, "my stroke")
+
+    expect_equal(res$fill, list(color = "my fill color"))
+    expect_equal(res$stroke, list(color = "my stroke color"))
   })
-  
+
   test_that("with font, no fill, and stroke", {
-    res <- create_style("my font", NULL, "my stroke")
-    
-    expect_true(length(res) == 2)
+    res <- create_overlay_style(
+      font_color = "my font color",
+      font_size = "my font size",
+      fill_color = NULL,
+      stroke_color = "my stroke color"
+    )
+
+    expect_type(res, "list")
+    expect_length(res, 2)
     expect_named(res, c("font", "stroke"))
-    expect_equal(res$font, "my font")
-    expect_equal(res$stroke, "my stroke")
+
+    expect_equal(res$font, list(color = "my font color", size = "my font size"))
+    expect_equal(res$stroke, list(color = "my stroke color"))
   })
-  
-  test_that("with font, fill and no stroke", {
-    res <- create_style("my font", "my fill", NULL)
-    
-    expect_true(length(res) == 2)
+
+  test_that("with font, fill, and no stroke", {
+    res <- create_overlay_style(
+      font_color = "my font color",
+      font_size = "my font size",
+      fill_color = "my fill color",
+      stroke_color = NULL
+    )
+
+    expect_type(res, "list")
+    expect_length(res, 2)
     expect_named(res, c("font", "fill"))
-    expect_equal(res$font, "my font")
-    expect_equal(res$fill, "my fill")
+
+    expect_equal(res$font, list(color = "my font color", size = "my font size"))
+    expect_equal(res$fill, list(color = "my fill color"))
   })
-})
 
-describe("create_font works", {
-  test_that("with color and size", {
-    res <- create_font("my color", "my size")
-    
-    expect_true(length(res) == 2)
-    expect_named(res, c("color", "size"))
-    expect_equal(res$color, "my color")
-    expect_equal(res$size, "my size")
-  })
-  
-  test_that("with no color, and size", {
-    res <- create_font(NULL, "my size")
-    
-    expect_true(length(res) == 1)
-    expect_named(res, c("size"))
-    expect_equal(res$size, "my size")
-  })
-  
-  test_that("with color and no stroke", {
-    res <- create_font("my color", NULL)
-    
-    expect_true(length(res) == 1)
-    expect_named(res, c("color"))
+  test_that("with only font_color", {
+    res <- create_overlay_style(font_color = "my font color")
+
+    expect_type(res, "list")
+    expect_length(res, 1)
+    expect_named(res, c("font"))
+
+    expect_equal(res$font, list(color = "my font color"))
   })
-})
 
-describe("create_fill works", {
-  test_that("with color", {
-    res <- create_fill("my color")
-    
-    expect_true(length(res) == 1)
-    expect_named(res, c("color"))
-    expect_equal(res$color, "my color")
+  test_that("with only font_size", {
+    res <- create_overlay_style(font_size = "my font size")
+
+    expect_type(res, "list")
+    expect_length(res, 1)
+    expect_named(res, c("font"))
+
+    expect_equal(res$font, list(size = "my font size"))
   })
-  
-  test_that("with no color", {
-    res <- create_fill(NULL)
-    
-    expect_true(length(res) == 0)
+
+  test_that("with only fill_color", {
+    res <- create_overlay_style(fill_color = "my fill color")
+
+    expect_type(res, "list")
+    expect_length(res, 1)
+    expect_named(res, c("fill"))
+
+    expect_equal(res$fill, list(color = "my fill color"))
   })
-})
 
-describe("create_stroke works", {
-  test_that("with color", {
-    res <- create_stroke("my color")
-    
-    expect_true(length(res) == 1)
-    expect_named(res, c("color"))
-    expect_equal(res$color, "my color")
+  test_that("with only stroke_color", {
+    res <- create_overlay_style(stroke_color = "my stroke color")
+
+    expect_type(res, "list")
+    expect_length(res, 1)
+    expect_named(res, c("stroke"))
+
+    expect_equal(res$stroke, list(color = "my stroke color"))
   })
-  
-  test_that("with no color", {
-    res <- create_stroke(NULL)
-    
-    expect_true(length(res) == 0)
+
+  test_that("with no arguments", {
+    res <- create_overlay_style()
+
+    expect_type(res, "list")
+    expect_length(res, 0)
   })
+
 })
 
 describe("build_bpmnContent works", {
@@ -153,11 +166,11 @@ describe("build_bpmnContent works", {
       ),
       enableDefaultOverlayStyle = TRUE
     )
-    
+
     expect_true(length(res) == 2)
-    expect_named(res,  c("bpmnContent", "enableDefaultOverlayStyle"))
+    expect_named(res, c("bpmnContent", "enableDefaultOverlayStyle"))
   })
-  
+
   test_that("with xml_doc and overlays", {
     res <- build_bpmnContent(
       xml2::read_xml(
@@ -166,13 +179,13 @@ describe("build_bpmnContent works", {
       enableDefaultOverlayStyle = FALSE,
       overlays = "this"
     )
-    
+
     expect_true(length(res) == 3)
     expect_named(res, c("bpmnContent", "enableDefaultOverlayStyle", "overlays"))
-    
+
     expect_equal(res$overlays, list("this"))
   })
-  
+
   test_that("with xml_doc and overlays is list", {
     res <- build_bpmnContent(
       xml2::read_xml(
@@ -184,11 +197,11 @@ describe("build_bpmnContent works", {
         create_overlay("bpmn_element_id_2", "9")
       )
     )
-    
+
     expect_true(length(res) == 3)
     expect_named(res, c("bpmnContent", "enableDefaultOverlayStyle", "overlays"))
   })
-  
+
   test_that("with character and no overlays", {
     res <- build_bpmnContent(
       paste(
@@ -199,21 +212,21 @@ describe("build_bpmnContent works", {
       ),
       enableDefaultOverlayStyle = TRUE
     )
-    
+
     expect_true(length(res) == 2)
     expect_named(res, c("bpmnContent", "enableDefaultOverlayStyle"))
   })
-  
+
   test_that("with character and no overlays", {
     res <- build_bpmnContent(
       system.file("examples/Email_Voting.bpmn", package = "bpmnVisualizationR"),
       enableDefaultOverlayStyle = TRUE
     )
-    
+
     expect_true(length(res) == 2)
     expect_named(res, c("bpmnContent", "enableDefaultOverlayStyle"))
   })
-  
+
   test_that("error", {
     expect_error(build_bpmnContent(iris))
   })
@@ -221,7 +234,7 @@ describe("build_bpmnContent works", {
 
 test_that("not_null_list works", {
   res <- .not_null_list(x = 1, y = NULL)
-  
+
   expect_true(length(res) == 1)
   expect_named(res, c("x"))
 })
\ No newline at end of file